SPROUT INHIBITOR FOR POTATOES

Abstract: The invention relates to a sprout inhibitor for potatoes which, as the main component, contains rape oil methylester and/or specific long-chain alcohols, eventually in mixture with the medium- and/or long-chain alcohols known for said purpose, and/or ethereal oil and/or the known chemical sprout-inhibiting agents, or to the use of rape oil methylester alone or the use of C18 to > C36-alcohols such as Espum EGA 162 (now Dehysan) alone, or in a mixture with rape oil methylester and/or other known sprout-inhibiting agents.

Description: Sprout Inhibitor for Potatoes The invention relates to a sprout inhibitor for potatoes, which substantially consists of rape oil methylester and/or long-chain alcohols or a composition based on rape oil methylester and/or long-chain alcohols. The potatoes harvested in the fall are frequently expected to be stored through the winter and far into the coming spring at least until early potatoes are available again. Even with cool storage of potatoes, as it is usually done in the potato-processing industry, the potatoes start to sprout after a few weeks even when stored at 6 to 8°C, and they are considerably sprouted after three to four months- The use of sprout-inhibiting agents is known since a long time. Very old sprout inhibitors are certain ethereal oils, in particular of the peppermints, and also of the "muna" plant, which is related to the peppermints. Peppermint oils and "muna" oils are, of course, relatively expensive, εo that any industrial application only on the basis of said ethereal oils is hardly feasible. The chemical agents used recently for sprout inhibition in connection with potatoes include propham, i.e. isopropyl- phenyl carbamate, also in combination with chloropropham; however, the compound has a herbicidal effect, so that its-use is not absolutely safe. Also known are medium-chain and higher-chain alcohols, in particular C-^-^^ lcoholε, which are collected in industry, whereby said alcohols are frequently combined with propham and/or chloropropham. As state of the art, reference is made to, for example the DD-patents 209 378, 205 600, 147 039, 146 237 and 138 731, as well as to O/PCT 93/00008, which show the use of long-chain alcohols r if necessary in combination with prophamand/or chloro¬ propham, whereby DD-PS 209 378 also shows medium-chain alcohols of Cg-C 14 ; DD-PS 205 600 shows the addition of m-chloro- naphthalene, and DD-PS 138 731 shows a combination of higher alcohols with the main components nonanol and decanol, and O 93/00008 shows aromatic aldehydes or alcohols or thymol or mixtures thereof. EP 0 287 946 A2 describes the use of an ethereal oil from a mentha type, in particular oils of entha piperita L, as well as again peppermint oil and oils of different types of mint. The drawback of all of said sprout inhibitors is that.they supply only rather moderate results in spite of the use of relatively large amounts, and that with the exception of the ethereal oils, their utilization for the preservation of foods is actually undesirable because they are not derived from natural products. As mentioned above, the exclusive use of ethereal oils is prohibitive for practical reasons because the amounts required even with storage with exclusion of air generally come to 10 to 20 ml oil per 50 kg potatoes with a storage duration of 50 days, and to about twice said amount with a storage duration of 100 days and longer, provided the storage conditions lead to only minor loss of the oils, and that the potatoes are stored at +3 to +8 β C. With the alcohols and the other agents specified above, there arises the problem of distribution, and with a mixture consisting of, for example C2 1 ~ -C 23 - lcoholε with a component of 0.25 to 0.50 mass-% isopropylphenyl carbamate used with a concentration of 200 g active substance per ton of potatoes to be treated, a rather good result was obtained with aggravated storage at 21°C over three weeks, starting with an addition of 0.5% isopropylphenyl carbamate; however, as mentioned in the foregoing, the use of this herbicidal substance is extremely undesirable because it never can be assured that nothing of this substance penetrates through the potato peel into the potato itself. Now , it has been found that the use of rape oil methylester as carrier for alcohols, namely all alcohols known from the state of the art and used for this purpose, and also with the ethereal oils known from the state of the art, or mixtures of alcohols with said ethereal oils supplies very good results with respect to sprout inhibition and inhibition of the start of rot with the potatoes, and that rape oil methylester itself, without addition, leads to very good results with respect to sprout inhibition, and to exceptionally good results with respect to rot inhibition. Of course, this applies also if. rape oil methylester is used as carrier for propham or chloropropham, hence isopropyl¬ phenyl carbamate or its derivative, which, however, causes certain concerns in terms of food technology, as mentioned a number of times. Accordingly, the invention lies in the utilization of rape oil methylester as sprout inhibitor, if need be in mixture with the known medium- and long-chain alcohols and /or ethereal oils and/or the known chemical sprout- inhibiting agents, whereby combinations of rape oil methylester, alcohol and, if need be, one of the aforementioned ethereal oils, in particular peppermint oil, are preferred for the best results. However, rape oil methylester itself suffices for technical storage purposes over not- too-long time periods with cooling to 6 to 8°C. The term "medium- and long-chain" alcohols means Cg to >C 36 alcohols , in particular Cg to C l4 and C^ 7 to C 24 alcohols , as well as C^g to C 36 alcohols with a component of ^ 3 g- aicohols, as they are commercially available as Espum EGA 162, now Dehysan®. Espum (Dehysan) has not yet been used for sprout inhibition, so that its use alone or in the claimed mixtures is the object of the present invention as well. Especially if used alone or as predominant part of the composition it is preferably used as an aqueous emulsion f.i. containing 15-40% by weight of Espum (Dehysan), prefera¬ bly 20-30% by weight. Well known commercially available emulsifiers may be used in a suitable amount. T he term "rape oil methylester" relates to the esterified fatty acids of the rape oil, which are collected upon saponification of the latter. This is a commercial product that is relatively inexpensive and available in good quality. The term "rape oil" not only relates to the earlier rape oil with the rather high content of erucic acid, but particularly includes also the oil of the varieties of rape grown at the present time, which instead of about 48% erucic acid haveonly about 0.5%, and about 63% oleic acid instead the earlier 15%, and about 20% linoleic acid instead of 13.5%, with about the same contents of linolenic acid, eicosenic acid, palmitic acid, hexadeceic acid and docosadienic acid, thus the oil of the so-called double-zero rape varieties, where both the erucic acid and the glycosinolate contents each come to <1%. Rape oil methylesters, in particular thus from the oil of the double-zero varieties grown now, are safe in terms of health, and, when used as sprout inhibitors or as the basis of the sprout inhibitors, do not damage the potatoes; also, no relevant change occurs, for example in the nitrate content, in the content of reduced sugar and diεaccharides, and in the other properties relevant to potatoes, and the potatoes stored therewith still showed in the sensorial test after 19 weeks of storage the typical potato flavor without foreign flavor or foreign odor, with good solid appearance and without noticeable changes in color. Rape oil methylester can be easily sprayed for liquid atomization (in particular swingfog) with or without addition of the known sprout-inhibiting agents, in¬ cluding the chemical ones. The spray mist deposits well on and between the potatoes even with greater layer thickness and still shows an adequate effect in the mass of the stored potato. It may however also be used in form of an aqueous emulsion, using well known commercial emulsifiers in a suitable amount. The amount applied of rape oil methylester and/or long-chain alcohol alone or plus the other active ingredients mentioned comes to about 50 ml to 100 ml/ton, which is very little, considering the fact that the commercial formulas consisting of higher alcohols and propham with silicic acid filler, dinitrosopentamethylene tetramine, PVC-powder and kaolin are used in a quantity of about 220 g/ton, and about 40 g/ton is used when chloropropham is utilized alone, whereas ethereal oils have to be used in an amount of about 50 ml/50 kg with a storage duration of 100 days and more, which seems always necessary in practical life. The invention is explained by the following examples: Example 1 The rape oil or the preparation based on rape oil was always distributed over and onto the stored potatoes by liquid atomization (swingfog). The following four sprout inhibition tests were scheduled for the first test: Four (4) lots of 40 kg potatoes each of the Christa variety were treated with compositions based on rape oil methylester with a solidification point of -5°C and higher alcohols (Espum EGA 162) substantially consisting of 70% Cιg" C 6 and 30% >C,,- with a solidification point of +5°C, and in one case with a component of peppermint oil. A blind test was carried out at the same time without any addition. The composition of the sprout inhibitor used in the specified amount was as follows: Table 1 Test Alcohol Oil Peppermint Amount Active component component component used substance (%) (%) % ml/ton ml ton In the present case, the. term "active substance n means alcohol + peppermint, thus the component used in addition to rape oil methylester. The potatoes were stored for 19 weeks at 6 to 8° C and subsequently exami¬ ned. The results are summarized in the following tables 2 and 3. Table 2 EVALUATION OF SPROUT INHIBITION TEST OF THE EXAMPLE CO c CrD Potato variety: Christa Duration of storage: 19 weeks CO _ mc 33 cr 3 The sensorial test of these fresh potatoes from the sprout inhibition test led to the following result. The potatoes of the Christa variety were tasted after a storage time of 19 weeks. For sprout inhibition, the samples were treated with the following substances: Sample 1 : Rape methylester mixed with long-chain alcohols at a ratio of 70:30 Sample 2: Rape methylester mixed with long-chain alcohols at a ratio of 60:40 Sample 3: Rape methylester mixed with long-chain alcohols and peppermint oil at a ratio of 70:25:5 Sample 4: without any sprout-inhibiting agent = standard Table 3 Evaluation The samples of tests 1, 2 and 3 did not show any significant sensorial differences compared to the untreated fresh potatoes. The potatoes of test 4 did not show any foreign flavor; however, they wrinkled during storage and were slightly more watery immediately after peeling. Example 2 This example shows the use of rape oil methyl ester alone and in combination with alcohol and pepper mint oil. The potatoes, which were used in each of tests 1 to 5 in an amount of 40 kg, and in an amount of 20 kg in comparative test 6, were stored over 9 weeks at 6 to 8°C. Only rape oil methylester was used in test 1, and in tests 2 and 3 as well as 5 treatment was carried out with a mixture of rape oil methylester with a solidification point of -5°C and higher alcohols (Espum EGA 162) substantially consisting of 70% Ci8-C 36 and 30% C36 with a solidification point of +5"C, and in test 4 with a component of peppermint oil. No treatment was carried out in test 6 "control". Consequently the conditions were substantially the same as in the comparative test according to example 1. The composition of the sprout inhibitor and the quantities used were as shown on table A . Table 4 SPROUT INHIBITION TEST CD O _E rπ Sample size 4 x 20 kg Quantity used 4 ml Air circulation time 20 min After-storage 48 h Storage basement, each test quantity stored on separate pallet In this test too, the term "active substance" means alcohol + peppermint oil and, therefore, is the component used in addition to rape oil methylester. The potatoes were stored for 66 days at 6 to 8°C and were then examined. The results are summarized in the following table 5: Table 5 EVALUATION OF THE SPROUT INHIBITION TEST The share of rot in test 4 and also with comparative test 6 (untreated control) was practically zero. However, sprout inhibition was very good with test A , and very poor with control test 6. Example 3 In a further test the long-chain alcohol Espum EGA 162, now marketed as Dehysan was used alone and compared with rape oil methylester alone and peppermint oil. The effectiveness of the alcohol (Espum, now Dehysan) is about the same as that of the rape oil methylester alone. Addition of 5% by weight of peppermint oil in both cases, that is 95% by weight alcohol or rape oil methylester plus 5% by weight peppermint oil clearly gives a still better result. The amount used was 50 ml/t in each case. Due to the high viscosity of the long-chain alcohol it was difficult to atomize it sufficiently. Thus, in another experiment the alcohol was used as an aqueous emulsion containing 25% by weight of the alcohol with a commerci¬ ally available fatyalcohol polyglycol ether sulfate as an emulsifier in an amount of about 1 g/l emulsion. The results were somewhat better than using the non-emulsified alcohol as such.

Claims: C AIMS 1. Sprout inhibitor for potatoes, characterized in that it contains as the main component rape oil methylester in mixture with medium- and/or long-chain alcohols known for said purpose, and/or ethereal oil and/or the known chemical sprout-inhibiting agents. 2. Sprout inhibitor according to claim 1, characterized in that it contains more than 50% by weight rape oil methylester and less than 50% by weight of the known sprout-inhibiting agents. 3. Sprout inhibitor according to claim 1 or 2, characterized in that it contains a least 60% by weight rape oil methylester and up to 40% by weight medium- and/or long-chain alcohols. 4. Sprout inhibitor according to claims 1 to 3, characterized in that apart from rape oil methylester itadditionally contains up to 10% by weight, particularly about 5%by weight ethereal oil, in particular peppermint oil, and/or 0.1 to 1% by weight of a known chemical sprout-inhibiting agent, in particular propham and/or chloropropham. 5. Sprout inhibitor according to claims 1 to 4, characterized in that it consists of more than 70% by weight, in particular 90 to 99% by weight rape oil methylester. 6. The use of rape oil methylester alone or in a mixture according to claims 1 to 5, as sprout inhibitor during the storage of potatoes. 7. Use of long-chain alcohols substantially consisting of 70% C 18 -C 36 and 30% > C 36 , in particular Espum EGA 162 (now Dehysan) alone or in mixture according to claims 1 to 5, as sprout inhibitor during the storage of potatoes. 8. Use according to claim 6 or 7 by means of liquid atomization, in particular swingfog. 9. Use according to claim 6, 7 or 8, in amounts of 50 to 100 ml sprout inhibitor per ton of potatoes. 10. Use of long-chain alcohols alone according to claim 7 in form of an aqueous emulsion, especially an emulsion having 15-40% by weight of the alco¬ hols and preferably additionally 5% by weight, based on alcohols of ethereal oil.

Inventors: HENNING DIETHART, ROBL GOTTFRIED, WINKELMANN HANS-HEINRICH, HENNING, DIETHART, ROBL, GOTTFRIED, WINKELMANN, HANS-HEINRICH
Applicants: PFANNI WERKE GMBH & CO KG, PFANNI-WERKE GMBH & CO. KG
Application year: 1994
Main classification: A01N37
IPC codes: A01N31, A01N37